This is a tool created by Negative Entropy to view and lookup data from many world downloads and years. You can find signs, void holes, banners, shulkers, echests, and spawners.

You are even able to search specific text and find coordinates of signs that contain it!

This is a project created by daporkchop and his team. For more info see the YouTube page here: https://www.youtube.com/@2b2tmapping80/videos. There are many world downloads of the map you can view including the 256K one.